Biopharmaceutical company AN2 Therapeutics Inc (Nasdaq: ANTX) announced on Monday an amendment to its statistical analysis plan for the Phase 3 EBO-301 trial, designating the Quality of Life - Bronchiectasis (QOL-B) respiratory domain patient-reported outcome (PRO) instrument as the primary efficacy endpoint. This follows the company's Phase 2 results, which suggested potential clinical proof-of-concept for epetraborole in treatment-refractory Mycobacterium avium complex (MAC) lung disease.

The company aims to release topline Phase 3 data by Q2 2025, pending any FDA feedback. The decision to select QOL-B as the primary endpoint aligns with the FDA's 2023 guidance on non-tuberculous mycobacteria (NTM) drug development and mirrors the approach used in Insmed's confirmatory study for Arikayce in MAC patients.

In Phase 2, epetraborole demonstrated nominal statistical superiority versus placebo, with a change in the QOL-B respiratory domain PRO score showing a significant difference at month 6 (p=0.0365). Blinded psychometric analyses further confirmed the reliability and clinical relevance of the QOL-B and MACrO2 PRO scores as measures of treatment response in this patient population.

AN2 reported Phase 2 topline results in August 2024, while ongoing Phase 3 data remains blinded and under review. The company is now assessing future development paths for treatment-refractory MAC (TR-MAC).